The present invention relates to an electrophotographic copying machine having a removable process unit and in particular to a copying machine comprising a structural housing, means in said housing for supporting an original, a scanning device for optically scanning said original, a process unit including a photoconductive member, a toner supply means and a developing device, said process unit being conditioned by said scanning device for forming a latent image of said original on said photoconductive member, said developing device carrying the toner supplied by said supplying means to develop said latent image.
In a known copying machine a process unit is removably mounted on the machine and is provided with a photoconductive endless belt wound around a pair of rollers rotatably mounted on an auxiliary frame carried by the process unit. The photoconductive belt is tensioned on the rollers by a pair of springs urging against the bearings of one of the rollers.
However, when the exhausted photoconductor is to be replaced, the auxiliary frame must be separated from the process unit and the tension applied to the belt must be released, resulting in complex operations and in waste of time.